Multiple Sclerosis (MS) is predominantly a disease of women of northern European origin and afflicts up to three million people worldwide. In the United States it is estimated that 400,000 people are affected. It is thought to be an autoimmune disorder and typically strikes young adults, causing a wide variety of symptoms that are often mistaken for other diseases. These symptoms stem from disruption of the central nervous system (CNS) and may include blurred or double vision; weakness in the arms or legs; changes or difficulties in balance, coordination and gait; bladder and/or bowel dysfunction; and emotional disturbances. Each patient may present a little differently and there may have been episodes in the past which were barely noticed by the patient at the time. It is difficult to firmly diagnose MS, especially if there has been only one symptomatic episode. This leaves patients and their doctors waiting months or years for a relapse to confirm that the symptoms are due to MS.
MS is a demyelinating disease, where myelin, the insulating layer on nerve fibers, is destroyed in the CNS, which consists of the brain, optic nerves, and spinal column. There is an accompanying inflammatory response and the blood brain barrier (BBB) is breached. Axon damage can occur and the optic nerve is commonly affected. Myelin damage makes it more difficult for nerves to transmit impulses, leading to symptoms of MS. The diagnostic McDonald Criteria (1) were revised in 2005 to include magnetic resonance imaging (MRI) criteria of different types of lesions of the brain and spinal cord in the diagnosis of MS. Prognosis is difficult to determine, and many brain lesions do not necessarily correlate with severity of disease. There are medications available to alleviate some symptoms and a few others to modify and hopefully delay the onset or severity of relapses of MS.
The most common form of MS is relapsing-remitting multiple sclerosis (RRMS), which is characterized by symptomatic episodes separated in time, with partial or complete recovery of an apparently normal state between relapses. It often converts to secondary progressive MS after several years, where there is a steady worsening of symptoms. A minority of patients have Primary Progressive MS which presents as a continuous slow worsening of the disease state. An even smaller minority of patients is diagnosed with Progressive-Relapsing MS, where in contrast to RRMS, there is a continuous worsening of their condition between acute episodes. A first episode is referred to as Clinically Isolated Syndrome (CIS) pending a more certain diagnosis of MS corresponding to clinical signs and/or brain lesions visualized by MRI, or possibly a spinal tap to check for immunoglobulin oligoclonal bands (OCB) in the cerebral spinal fluid (CSF). None of these diagnostic methods is 100% specific. (2). Its drawbacks include the expense and the fact that a patient must wait one to three months between scans to determine if new lesions have formed during the intervening period. There is a clear need for identification of a biomarker or set of biomarkers that indicate presence and/or severity of disease for MS patients. A simple blood test would be ideal for diagnosing MS, however at this time, no commercial blood test exists.
Early diagnosis of MS is thought to be increasingly important, as much of the damage occurs early in the disease process. The earlier the diagnosis, the earlier disease-modifying treatment can begin and progression of the disease and associated disability can hopefully be slowed.
The present invention features a method of detecting multiple sclerosis or a risk of multiple sclerosis. The method comprises detecting a multiple sclerosis-associated biomarker, e.g., an antigen, wherein detecting an elevated level of such multiple sclerosis-associated biomarker indicates the presence of multiple sclerosis or a risk of multiple sclerosis.